Virtual autocalibration of sensors

ABSTRACT

The present disclosure describes methods and systems for virtually calibrating geometric sensors with overlapping fields of view. In some embodiments, a geometric sensor may be virtually calibrated by applying a correction value to profile data obtained by the geometric sensor to generate adjusted profile data. The correction factor may be determined based at least in part on X-Y offsets and/or rotational offsets of prior profile data obtained by the geometric sensor relative to corresponding profile data obtained by a reference geometric sensor, and may be recalculated or updated as new sets of profile data are obtained. The adjusted profile data may be used in place of the original profile data in various data processing operations to functionally offset a positional error of the geometric sensor.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/182,569, filed Nov. 6, 2018 which claims priority to U.S. ProvisionalPatent Application No. 62/582,305, filed on Nov. 6, 2017, all entitled“VIRTUAL AUTOCALIBRATION OF SENSORS,” the disclosures of which areincorporated by reference herein.

BACKGROUND

Large sawmills typically cut logs into lumber in stages. In the firststage, or primary breakdown, the logs are rotated to a desired angle andconveyed through chippers and/or saws that cut the logs into cants. Somemills cut flitches from the cants by cutting the cants longitudinallyalong planes generally parallel to the machined faces. Other millsprofile side boards along the machined faces of the cants, and the cantsare then cut longitudinally to release the side boards. In both cases,the log is cut into a center cant and one or more additional pieces (orchipped into a center cant and chips) during this stage.

In the second stage, or secondary breakdown, the center cant is cut intocenter boards by a gang saw, any flitches are cut into outer boards byan edger, and all of the boards are trimmed to desired lengths.

In many sawmills, some or all of the machine centers are controlledautomatically by a control system based on workpiece position,orientation, dimensions, and other information obtained by scanners. Theworkpiece is conveyed through a scan zone upstream of the machinecenter, and the computer system uses the profile data to position and/orcut the workpiece into the desired pieces.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments will be readily understood by the following detaileddescription in conjunction with the accompanying drawings. Embodimentsare illustrated by way of example and not by way of limitation in thefigures of the accompanying drawings.

FIGS. 1A and 1B show schematic diagrams of multi-zone and single-zonevirtual calibration systems, respectively;

FIG. 2A-2E illustrate examples of lineal scanners with geometric sensorsarranged in various configurations;

FIGS. 3A-3C illustrate examples of transverse scanners;

FIG. 4 shows a schematic diagram of profile data and a correspondingmulti-zone scanner arrangement;

FIG. 5 shows a schematic diagram of profile data and a correspondingsingle-zone scanner arrangement;

FIG. 6 is a flow diagram of a virtual calibration method;

FIGS. 7-9 are flow diagrams of processes of the virtual calibrationmethod of FIG. 6;

FIG. 10 shows a schematic plan view of lumber processing lines with avirtual calibration system;

FIG. 11 shows a side elevational view of a lumber processing line with avirtual calibration system, and corresponding computer systemoperations;

FIG. 12 is a flow diagram of a multi-zone virtual calibration method;

FIG. 13 is a flow diagram of a single-zone virtual calibration method;

FIG. 14 is a flow diagram of a virtual calibration process; and

FIG. 15 is a schematic diagram of a computer system suitable forperforming virtual calibration methods, all in accordance with variousembodiments.

DETAILED DESCRIPTION OF DISCLOSED EMBODIMENTS

In the following detailed description, reference is made to theaccompanying drawings which form a part hereof, and in which are shownby way of illustration embodiments that may be practiced. It is to beunderstood that other embodiments may be utilized and structural orlogical changes may be made without departing from the scope. Therefore,the following detailed description is not to be taken in a limitingsense, and the scope of embodiments is defined by the appended claimsand their equivalents.

Various operations may be described as multiple discrete operations inturn, in a manner that may be helpful in understanding embodiments;however, the order of description should not be construed to imply thatthese operations are order dependent.

The description may use perspective-based descriptions such as up/down,back/front, and top/bottom. Such descriptions are merely used tofacilitate the discussion and are not intended to restrict theapplication of disclosed embodiments.

The terms “coupled” and “connected,” along with their derivatives, maybe used. It should be understood that these terms are not intended assynonyms for each other. Rather, in particular embodiments, “connected”may be used to indicate that two or more elements are in direct physicalor electrical contact with each other. “Coupled” may mean that two ormore elements are in direct physical or electrical contact. However,“coupled” may also mean that two or more elements are not in directcontact with each other, but yet still cooperate or interact with eachother.

For the purposes of the description, a phrase in the form “A/B” or inthe form “A and/or B” means (A), (B), or (A and B). For the purposes ofthe description, a phrase in the form “at least one of A, B, and C”means (A), (B), (C), (A and B), (A and C), (B and C), or (A, B and C).For the purposes of the description, a phrase in the form “(A)B” means(B) or (AB) that is, A is an optional element.

The description may use the terms “embodiment” or “embodiments,” whichmay each refer to one or more of the same or different embodiments.Furthermore, the terms “comprising,” “including,” “having,” and thelike, as used with respect to embodiments, are synonymous.

As used herein, the term “sensor” refers generally to a deviceconfigured to detect one or more physical characteristics of an object,such as a log, flitch, cant, board, or other type of wood workpiece.Examples of sensors include, but are not limited to, imaging devices(e.g., line scan cameras, video cameras, fiber optic sensors, laserprofile sensors, x-ray/tomography sensors, microwave sensors, ultrasoundsensors, infrared sensors, etc.), and devices configured to detecttemperature, vibration, fluorescence, speed, density, moisture, and/orother characteristic(s) of the object.

The term “geometric sensor” refers more specifically to a deviceconfigured to measure the geometric profile of an object or portionthereof. Examples of geometric sensors include, but are not limited to,time-of-flight 3D sensors, laser triangulation sensors, structured-light3D sensors, modulated light 3D sensors, and computed tomography sensors.

As used herein, the term “scanner” refers to the geometric sensor(s)(and to the additional sensor(s), if any) positioned to detectworkpieces within a given scan zone. Some scanners may include only onegeometric sensor, which may be positioned above, below, or to one sideof the flow path. Other scanners may include two or more geometricsensors arranged around, above, below, across, along, and/or on oppositesides of the flow path, or in any other suitable manner. Some scannersmay include one or more other types of sensors in addition to geometricsensors. In some cases, a scanner may include two or more geometricsensors, or groups of geometric sensors, that are positioned to detectworkpieces within respective sub-zones of the scan zone. Again, thegeometric sensor(s) of each sub-zone may be arranged above, below,beside, around, across, and/or along the flow path, in any suitablemanner.

In various embodiments, a computing device may be endowed with one ormore components of the disclosed apparatuses and/or systems and may beemployed to perform one or more methods as disclosed herein.

A typical processing line has machine centers arranged along a path offlow and transports (conveyors, transfers, etc.) that move objects suchas wood workpieces through the machine centers along the path of flow.For example, a facility that produces solid lumber may have intake,primary breakdown, secondary breakdown, planer/dry mill, and/or otherprocessing lines. Scanners are used frequently in sawmills and otherproduction facilities to obtain information about the position,dimensions, and other attributes of a workpiece upstream of a machinecenter that will be used to process the workpiece.

For example, in some sawmills a log is conveyed through multiple scanzones upstream of a chipper. A computer system uses the profile data todetermine a desired rotational angle and orientation (e.g., horizontaland vertical offset and skew) for the log, as well as a cut solution forcutting the log into desired products (e.g., center boards and sideboards or outer boards). The log is turned, positioned, and chippedaccording to the cut solution and some or all of the resulting piecesare cut again, eventually yielding the desired cut products. The log maytravel through several scan zones before, during, and/or after thechipping and cutting procedures, and the profile data collected in thescan zones may be used to control corresponding machine centers.

In some cases, profile data from two scanners or geometric sensors mustbe matched to one another. For example, a log may be conveyed through afirst scan zone upstream of a log turner, and the corresponding profiledata may be used to determine a desired rotational position for the logabout its longitudinal (Z) axis, and/or a desired lateral offset or skewangle, relative to the log's initial rotational position. A computersystem might need to match the profile data to profile data collected ina second scan zone at the log turner in order to monitor the rotation ofthe log and control the log turner to turn the log accurately to thedesired position before the log is thumped onto a sharp chain forchipping or cutting. Likewise, the computer system may need to match theprofile data from the second scan zone to profile data from a third scanzone further downstream along the sharp chain to determine the finalposition of the log on the sharp chain and/or calculate or modify a cutsolution or cut pattern for the log to offset a difference between thedesired position and the final position.

In other cases, processing a workpiece accurately may require matchingthe profile data from two sensors of the same scan zone. For example, ascanner with multiple geometric sensors might be used to scan flitchesupstream of an edger, and the profile data might be used to calculate acut solution for the flitches without reference to the original cutsolutions for the logs. In such cases the computer system might need tomatch or align the data from the adjacent geometric sensors to generatea virtual model of the workpiece, identify defects, calculate or modifya cut solution/pattern, assess the position or orientation of theworkpiece relative to a machine center, and/or generate controlinstructions to control a machine center to cut the workpiece correctly.In addition to matching profile data from geometric sensors of one scanzone, the profile data from those geometric sensors may also be matchedto profile data from another scanner or geometric sensors thereof.

Maintaining scanners and geometric sensors in precise alignment aids inthe matching process. If a scanner/geometric sensor is misaligned, thecomputer system may require more time to match the data, resulting inreduced line speeds. A misaligned sensor may also increase thelikelihood of an incorrect match. If the computer system matches theprofile data incorrectly, the computer system may generate controlinstructions that cause the workpiece to be positioned or cutincorrectly, resulting in waste and loss of profit.

The conventional way to maintain proper scanner/sensor alignment is tomanually calibrate each sensor. Conventional calibration methods requiremanual measurement and adjustment of the position of each scanner/sensorrelative to a fixed reference position, or relative to a temporarycalibration target placed at a known location. Performing thesemeasurements and adjustments with the necessary accuracy can bechallenging, labor-intensive, and time-consuming. The operator may berequired to reduce the operating speed of nearby equipment, or to stopthe entire processing line, while the sensors are being calibrated. Theassociated downtime is costly and undesirable. Moreover, vibration ofthe equipment during normal operation and/or sudden impacts such asthumping the log down onto the sharp chain may necessitate frequentrecalibration of the sensors, increasing downtime and further impactingprofits.

Embodiments of methods for automatic virtual calibration of geometricsensors, and corresponding virtual calibration systems, are describedherein. Such calibration techniques are described herein as ‘virtual’ inthe sense that the calibration is functional, performed by adjustingdata as opposed to physically moving the geometric sensor. In variousembodiments, a first geometric sensor may be functionally calibrated bydetermining a correction factor for that geometric sensor, based atleast on an X-Y offset of profile data from that geometric sensorrelative to reference profile data from another geometric sensor, andapplying the correction factor to a subsequent set of profile data fromthe first geometric sensor to thereby generate an adjusted set ofprofile data. Optionally, the correction factor may be an average of, orotherwise derived from, the X-Y offsets of multiple sets of profile datarelative to the corresponding reference sets of profile data.

Adjustments to profile data (e.g., adjustments to the transformationfunction(s) applied to the data)—as opposed to adjustments to thephysical position or orientation of scanners—may be made ‘on the fly,’while workpieces are being conveyed and cut. Moreover, such adjustmentsmay be done continuously or at frequent intervals to keep a scanner‘virtually’ calibrated despite exposure to vibration, impacts, and othersuch events. This may allow the processing line to continue operation asthe geometric sensors become misaligned, allowing the operator to delaymanual recalibration for longer periods of time and helping to reducethe number of unplanned stoppages. Virtual calibration may improve theperformance of computers and computer systems by making the profile dataeasier to match, thereby reducing the computational demands on theprocessor. Thus, embodiments of the present disclosure may help toreduce downtime associated with prior calibration methods, reduce thefrequency with which the operator must adjust the physical position(s)of the scanner(s), help to maintain or improve the accuracy with whichthe workpieces are cut by the machine centers, and/or improve theperformance of computers and computer systems used to match sets ofprofile data.

In various embodiments, a virtual calibration system may include atleast a first geometric sensor, a second geometric sensor, and acomputer system operatively coupled with the first and second geometricsensors.

In a multi-zone virtual calibration system, the first geometric sensorand the second geometric sensor may be positioned to scan objects (e.g.,pieces of wood) in corresponding first and second scan zones that arespaced apart along a path of flow.

In a single-zone virtual calibration system, the first and secondgeometric sensors may be positioned to scan objects (e.g., pieces ofwood) within a single scan zone.

Regardless, the computer system may virtually calibrate the firstgeometric sensor relative to the second geometric sensor, or vice versa,or both, based at least in part on overlapping profile data (i.e.,profile data collected by multiple geometric sensors for the sameportion of an object). In some embodiments, a virtual calibration systemmay function as both a single-zone and multi-zone system. For example, afirst group of geometric sensors and a second group of geometric sensorsmay be positioned to scan objects in first and second scan zones,respectively, and the computer system may virtually calibrate thegeometric sensors of each group relative to one another and virtuallycalibrate one group relative to the other group.

Turning now to the Figures, a schematic side elevational view of amulti-zone calibration system is shown in FIG. 1A and a schematic frontelevational view of a single-zone virtual calibration system is shown inFIG. 1B, all in accordance with various embodiments.

Referring first to FIG. 1A, in a multi-zone calibration system, at leasttwo scanners—each with at least one geometric sensor 102—may be arrangedalong a flow path to scan an object 2 at corresponding scan zones(dashed lines) as the object is moved along the flow path in a flowdirection (arrow) through the scan zones of the scanners. The geometricsensors 102 are positioned/oriented to scan at least a portion of theobject (e.g., an uppermost surface) at different locations, such thatthey obtain overlapping profile data. Therefore, although the fields ofview of the geometric sensors 102 may be spaced apart along the flowpath, the geometric sensors 102 are positioned to scan the same portionof the object and are thus considered to have overlapping fields ofview. In some embodiments, each scanner/scan zone may have multiplegeometric sensors 102 arranged around, above and below, and/or alongopposite sides of the flow path or in any other suitable manner.Regardless, the geometric sensors 102 may be operatively coupled with acomputer system 106. Computer system 106 may be configured to virtuallycalibrate one of the scanners/geometric sensors 102 relative to theother scanner/geometric sensor(s) 102, as described further below.

A single-zone virtual calibration system, as shown for example in FIG.1B, may include a scanner that has at least two geometric sensors 102arranged around, above and below, and/or along opposite sides of theflow path to scan an object 2 passing through the scan zone of thescanner. Some or all of the geometric sensors 102 may have overlappingfields of view (dashed lines). In some embodiments, the fields of viewmay overlap along a plane, such that the geometric sensors 102 scan thesame portion of the workpiece (e.g., the portion within the overlap zone104) simultaneously. In other embodiments the scan zone may havemultiple sub-zones, and the fields of view of the correspondinggeometric sensors 102 may be spaced apart along the flow path such thatthe portion of the object within the overlap zone 104 is scannedsequentially by the respective geometric sensors. In either case, theprofile data collected by the geometric sensors 102 may includeoverlapping profile data. The geometric sensors 102 may be operativelycoupled with a computer system 106. Again, computer system 106 may beconfigured to virtually calibrate one of the geometric sensors 102relative one or more of the other geometric sensors 102, as describedfurther below.

Some virtual calibration systems may include multiple scanners spacedapart along the flow path (e.g., as shown in FIG. 1A), each withmultiple geometric sensors 102 (e.g., as shown in FIG. 1B), and acomputer system (e.g., computer system 106) operatively coupled with thescanners/geometric sensors. The computer system may be configured tovirtually calibrate at least one of the scanners relative to another ofthe scanners, and to virtually calibrate at least one of the geometricsensors of a scanner relative to another geometric sensor of thatscanner.

Geometric sensors 102 may be any geometric sensors suitable formeasuring the 3D profile of an object, such as a piece of wood, bydetermining the distances between a reference location (e.g., thegeometric sensor) and a plurality of points along the outer surface ofthe object. In particular, geometric sensors 102 may be any geometricsensors suitable for measuring the 3D profile of a wood workpiece, suchas a stem, a log, a cant, a flitch, a slab, a board, or the like. Invarious embodiments, geometric sensors 102 may be laser profile sensors.Preferably, geometric sensors 102 are configured to obtain surfacemeasurement data (e.g., distance values), filter the obtained data, andconvert the filtered data to dimension (X-Y) coordinates (“datapoints”). Examples of suitable geometric sensors include, but are notlimited to, USNR Smart TriCam sensors with integral DSP processor framegrabber (e.g., for scanning flitches in a transverse orientation) andUSNR LPL or LPLe sensors (e.g., for scanning flitches in a linealorientation).

Some scanners may include geometric sensors arranged across thedirection of flow, over and/or under the flow path, to scan objectsmoving in a transverse orientation (with the long axis of the objecttransverse to the flow direction). Other scanners may include geometricsensors arranged around, above and below, and/or on opposite sides of,the flow path to scan objects moving in a lineal orientation (with thelong axis of the object generally parallel to the flow direction).Optionally, some or all of the geometric sensors of a scanner may bepositioned at angles to scan two corresponding surfaces of a workpiecewith cut faces/sides.

Examples of scanners with multiple geometric sensors 102 are shown inFIGS. 2A-3C, in accordance with various embodiments. Optionally, somescanners may include one or more other types of sensors 132 (e.g., colorvision cameras, grain angle sensors, x-ray sensors, ultrasound sensors)in addition to the geometric sensor(s) 102.

FIGS. 2A and 2B show perspective and front elevational views,respectively, of a scanner with five geometric sensors 102 arrangedaround the flow path, with the respective fields of view of adjacentgeometric sensors overlapping at overlap regions 104. FIGS. 2C-2E showfront elevational views of scanners with four geometric sensors 102(FIG. 2C) and two geometric sensors 102 (FIGS. 2D, 2E). FIG. 3A shows aschematic front elevational view of a transverse scanner, and FIGS. 3Band 3C show perspective and side elevational views, respectively, of atransverse scanner, all with multiple geometric sensors 102. Theseconfigurations are illustrated merely by way of example, and the numberand arrangement of scanners and geometric sensors will vary amongembodiments.

Referring again to FIGS. 1A and 1B, computer system 106 may include oneor more computers. In some embodiments, computer system 106 may furtherinclude one or more controllers (e.g., programmable logic controllersand/or motion controllers), position indicator devices, servers, and/oroutput devices, in any suitable number, type, and configuration.

In operation, as an object is moved along the flow path (e.g., on aconveyor) through the fields of view of the geometric sensors 102, theobject may be scanned by the geometric sensors 102. The profile datafrom one scanner/geometric sensor may be matched to correspondingprofile data from another scanner/geometric sensor for variousprocessing tasks, such as identifying changes in the position ororientation of the object or controlling a piece of equipment toreposition or cut the object correctly. If one of the geometric sensors102 is misaligned relative to the other, the profile data from themisaligned geometric sensor may be offset (e.g., rotationally and/oralong the X and/or Y axes) relative to the profile data from the othergeometric sensor.

FIGS. 4 and 5 are schematic illustrations of sets of profile dataobtained by respective geometric sensors, in accordance with variousembodiments. Because the geometric sensors have overlapping fields ofview (see insets), the sets of profile data include overlapping datapoints (arrows). The inset of FIG. 4 shows a schematic side elevationalview of a geometric sensor 102 a and a geometric sensor 102 b positionedto scan an object 2 in corresponding scan zones spaced apart along aflow path. In this example geometric sensor 102 b is misaligned relativeto geometric sensor 102 a. As a result, the set of profile data 138collected by geometric sensor 102 b is rotated by −10 degrees and offsetby 4.5 units along the X axis and 7 units along the Y axis relative tothe reference set of profile data 134 collected by geometric sensor 102a. The inset of FIG. 5 shows a schematic front elevational view of ageometric sensor 102 a and a geometric sensor 102 b positioned to scanan object 2 within a single scan zone, with the respective fields ofview overlapping at an overlap zone 104. In this illustration, geometricsensor 102 b is misaligned relative to geometric sensor 102 a. As aresult, the set of profile data 146 from geometric sensor 102 b isoffset by 0 degrees of rotation, 3 units along the X axis, and −2 unitsalong the Y axis relative to the reference set of profile data 144 fromthe geometric sensor 102 a. The units may be inches, centimeters, or anyother suitable unit of measure.

Such misalignments can be detrimental to the matching process. Thus, invarious embodiments, the computer system may be configured to perform avirtual calibration method to functionally offset a positional error, ormisalignment, of a geometric sensor relative to another geometric sensorby adjusting the profile data, as opposed to physically repositioningthe geometric sensor. In various embodiments, the computer system mayadjust a set of profile data based on the offset(s) of prior profiledata from that geometric sensor relative to corresponding profile datafrom another geometric sensor. The adjusted set of profile data may beused in place of the original profile data in processing tasks such asprofile matching, determination of object position, control ofcutting/handling equipment, and the like, and/or to detect and report amisalignment of a geometric sensor. In some embodiments, the magnitudeof the adjustments can be used to detect and report a misalignment of ageometric sensor.

FIGS. 6-9 illustrate flow diagrams of a virtual calibration method andprocesses thereof, all in accordance with various embodiments.

Referring first to FIG. 6, method 600 may begin at block 601. At block601, a computer system (e.g., computer system 106) may receive aninitial set of profile data obtained by one or more first geometricsensors, and a reference set of profile data obtained by one or moresecond geometric sensors, for an initial object. The initial set andreference set may be received in any order, or simultaneously, dependingon the application and sensor arrangement.

The first and second geometric sensors may be configured to obtainsurface measurement data (e.g., distance values), filter the obtaineddata, and convert the filtered data to data points. Each set of profiledata may include multiple groups of data points, with each groupincluding the dimension (X,Y) coordinates of surface points at intervalsalong the length (Z-axis) of the workpiece. Thus, each group of datapoints may be a ‘frame’ that represents the outer shape of acorresponding cross-section (or portion thereof) of the object.

In some embodiments, the first geometric sensor(s) may be geometricsensor(s) of a first scanner, and the second geometric sensor(s) may begeometric sensor(s) of a second scanner located upstream or downstreamof the first scanner (e.g., geometric sensors 102 a and 102 b,respectively, FIG. 4). Alternatively, the first and second geometricsensors may be geometric sensors of a single scanner (e.g., geometricsensors 102 a, 102 b, 102 c, and/or 102 d, FIG. 5). Regardless, thefirst geometric sensor(s) and the second geometric sensor(s) may bepositioned to scan at least a portion of the initial object, such thatthe corresponding sets of profile data include overlapping profile data(e.g., data points that represent approximately the same location alongthe surface of the workpiece).

In some embodiments, the initial object may be a wood workpiece, such asa log, stem, cant, slab, flitch, board, or other piece of wood, that isscanned by the first and second geometric sensors as it is moved throughthe respective scan zones of those geometric sensors. Alternatively, insome embodiments the initial object may be a calibration target. Acalibration target may be of any suitable size, material, and shape.Examples of calibration targets include, but are not limited to, solidor hollow objects that generally mimic the shape of a workpiece, fixedfiducials, and a conveyor or component thereof (e.g., a chain, belt, orframe), or other processing line equipment, within the respective fieldsof view of the first and second geometric sensors.

At block 603, the computer system may determine an offset value for theinitial set of profile data relative to the reference set of profiledata. An example of a process for determining an offset value is shownin FIG. 7. Referring to that Figure, at block 701 the computer systemmay align the initial set of profile data to the reference set ofprofile data. For example, if the first and second geometric sensors aregeometric sensors of separate scan zones, the computer system may alignthe profile data by identifying a frame (e.g., a cross-section) of thereference set of profile data that matches a frame of the initial set ofprofile data. The computer system may identify the matching frame of thereference set of profile data in any suitable manner, such as bypairwise comparison of frames or data points and selection of the matchwith the highest comparison score. The computer system may use thematching frames to align the sets of profile data. Alternatively, if thefirst and second geometric sensors are geometric sensors of a singlescanner, the computer system may align the sets of profile data byaligning the overlapping profile data. Again, the computer system mayalign sets of profile data in a pairwise fashion. Alternatively, thecomputer system may align all of the geometric sensors of a given scanzone/scanner simultaneously based on the overlapping portions of data.

Optionally, if the first and second geometric sensors are geometricsensors of separate scanners, and the first geometric sensor(s) includesmultiple first geometric sensors, the method may proceed to block 703.At block 703 the computer system may align portions of the profile dataobtained by each of the respective first geometric sensors to thereference set of profile data. In other embodiments, block 703 may beomitted. For example, block 703 may be omitted if only one firstgeometric sensor is being virtually calibrated relative to only onesecond geometric sensor of a different scan zone, or if the first andsecond geometric sensors are geometric sensors of a single scan zone.

At block 705, the computer system may determine a rotational and/ortranslational difference of the initial set of profile data relative tothe reference set of profile data based on the alignment. Again, ifthere are multiple first geometric sensors, the computer system maydetermine a rotational and/or translational difference for each of thefirst geometric sensors relative to the reference set of profile data.In some embodiments blocks 701 and 703 may be performed simultaneously.For example, the computer system may use conventional image alignmentalgorithms or corresponding computer software that determines therotational/translational difference(s) in the process of aligning theprofile data, or vice versa.

At block 707 the computer system may store the determined rotationaland/or translational difference in a buffer as an offset value.Optionally, if there are multiple first geometric sensors and thecomputer system determines a rotational and/or translational differencefor each, the computer system may store each of the determinedrotational and/or translational differences in a corresponding buffer.Thus, in such embodiments, multiple buffers may be provided, and eachbuffer may be used to store the offset value(s) for a corresponding oneof the first geometric sensors. In other embodiments, the computersystem may determine only one offset value for a single first geometricsensor, or only one offset value for multiple geometric sensors, andstore the offset value in a single buffer. In some embodiments, theoffset value may be the actual offset of the initial set of profile datarelative to the reference set of profile data. For instance, if theinitial set of profile data is offset by 3 units along the X axis and −2units along the Y axis relative to the reference set of profile data,the offset value might be (3, −2). In other embodiments, the offsetvalue may be the positional change required to align the initial set ofprofile data with the reference set of profile data. For instance, ifthe initial set of profile data is offset by 3 units along the X axisand −2 units along the Y axis relative to the reference set of profiledata, the offset value might be (−3, 2). Regardless, the offset valuemay represent an X-Y offset of a set of profile data relative to acorresponding reference set of profile data. Optionally, the offsetvalue may represent a rotational value (e.g., expressed in degrees)instead of, or in addition to, an X-Y offset.

Referring again to FIG. 6, in some embodiments blocks 601 and 603 may berepeated multiple times, with profile data from additional objects,until a desired number of offset values are stored in the buffer(s). Forexample, upon initial startup of the virtual calibration system, blocks601 and 603 may be repeated until there are a predetermined number(e.g., 10, 25, 50) of offset values in the buffer(s).

In other embodiments, blocks 601 and 603 may be omitted, and method 600may begin at block 605. For example, upon initial startup of the virtualcalibration system, the computer system may assume the offset value(s)to be zero.

At block 605 the computer system may receive a set of profile dataobtained by the one or more first geometric sensors for an object. Ifthe method begins at block 605, the object may be the first objectscanned. Alternatively, if the method begins at block 601, the objectmay be the next successive object scanned after the initial object(s).In some embodiments the object may be a wood workpiece, such as a log,stem, cant, slab, flitch, board, or other piece of wood.

At block 607 the computer system may generate an adjusted set of profiledata for the object based at least on the corresponding set of profiledata and the offset value. An example of a process for generating anadjusted set of profile data is shown in FIG. 8. Referring now to thatFigure, at block 801 the computer system may determine a correctionvalue based at least on the offset value. In some embodiments, thecomputer system may use the most recently stored offset value for thecorresponding first geometric sensor as the correction value. In otherembodiments, the computer system may calculate the correction valuebased on a plurality of offset values stored in the correspondingbuffer. For example, in some embodiments the computer system maydetermine the correction value as the average of a desired number (e.g.,10, 25, 50) of the most recent offset values stored in the buffer. Inother embodiments the computer system may use an average or some otherfilter (e.g., median filter, trimmed mean, gaussian, etc.) to determinethe correction value. If the first geometric sensor(s) includes multiplegeometric sensors, and the computer system has determined correspondingoffset values for those geometric sensors, the computer system maydetermine a correction value for each one individually, based on theoffset value(s) stored in the corresponding buffer for that geometricsensor.

At block 803 the computer system may apply the correction value to theset of profile data to obtain the adjusted set of scan data for theobject. For example, if the offset value is the actualrotational/translational offset of an initial set of profile datarelative to the corresponding reference set of profile data, thecomputer system may apply the correction value to the new set of profiledata by subtracting the offset value from some or all of the data pointsof the new set of profile data. If the offset value is therotational/translational change required to align the initial set ofprofile data with the corresponding reference set of profile data, thecomputer system may apply the correction value to the new set of profiledata by adding the correction value to some or all of the data points ofthat set.

Referring again to FIG. 6, at block 609 the computer system may use theadjusted set of profile data, and/or send it to a machine center and/ora second computer system for use, in various processing tasks (e.g.,determining a change in position/orientation of the object, controllingcutting/positioning equipment to cut or position the object, determiningor modifying a cut solution for the object, etc.). Optionally, thecomputer system may generate and send commands to an output device(e.g., a monitor) to display the correction value. In some embodiments,the computer system may use the adjusted set of profile data to generatea 3D model of the object.

For example, the computer system may generate the 3D model by assemblingthe adjusted set of profile data. Alternatively, the computer system maygenerate the 3D model by interpolating between the groups of data pointsof the adjusted set of profile data to create new groups of data pointsat desired intervals along the longitudinal axis of the object (e.g., togenerate cross sections on ½ inch centers). The computer system may usethe 3D model to control cutting/positioning equipment to cut orreposition the object, to determine or modify a desired position for theobject, and/or to determine or modify a cut solution for the object. Asanother example, the computer system may compare the adjusted set ofprofile data and/or the 3D model to another adjusted set of profile dataand/or 3D model of the object to assess a change in theposition/orientation of the object.

Optionally, at block 611 the computer system may generate an alert basedat least in part on the offset value. An example of a process forgenerating an alert based at least in part on the offset value is shownin FIG. 9. Referring now to that Figure, at block 901 the computersystem may compare the correction value to a threshold value. Thethreshold value may represent a maximum permitted correction value. Atblock 903, the computer system may determine, based on the comparison,whether the correction value exceeds the threshold value. If thedetermined correction value exceeds the threshold value, at block 905the computer system may generate and send one or more commands to anoutput device (e.g., output device 128) to thereby cause the outputdevice to output an alert, such as a visual display and/or audiblealert. In other embodiments, the computer system may compare the offsetvalue to the threshold value instead of the correction value, determinewhether the offset value exceeds the threshold value, and send thecommand(s) to the output device in response to a determination that theoffset value exceeds the threshold value. Regardless, the alert messagemay recommend and/or instruct an adjustment to the position of acorresponding one of the geometric sensors. Some embodiments may omitblock 609 or block 611.

At block 613 the computer system may determine an offset value for the(unadjusted) set of profile data relative to a corresponding referenceset of profile data obtained by the second geometric sensor(s). Thecomputer system may determine the offset value in the same or similarmanner as described above with regard to block 603 and FIG. 7. Thecomputer system may receive the corresponding reference set of profiledata at block 613, or at block 605 or any of blocks 607-611.

In various embodiments, additional objects may be scanned in successionby the first and second geometric sensors, and the computer system mayrepeat blocks 605, 607, and 613 (and optionally, block 609 and/or 611)with some or all of the new sets of profile data and corresponding setsof reference profile data. In some embodiments, the correction value maybe recalculated for each successive workpiece. In other embodiments, thecorrection value may be recalculated for some, but not all, of thesuccessive workpieces. For example, the correction value may berecalculated for every second workpiece, every fifth workpiece, or thelike. As another example, the correction value may be recalculated atdefined times (e.g., 8 am each day), or upon the occurrence of aparticular event (e.g., at the beginning of each new shift in theproduction facility, or upon startup of the processing line after astoppage), or in response to input from an operator (e.g., through akeyboard, touchscreen, button, joystick, etc.).

Virtually calibrating geometric sensors/scanners on a continuous orsemi-continuous basis may help to maintain productivity by reducingunscheduled downtime along a production line. Without a virtualcalibration system, the operator may need to stop the production line tocorrect even a relatively small misalignment of a geometric sensor.Using virtual calibration methods may effectively increase the toleranceof the processing line to positional changes of geometric sensorsinduced by vibrations, impacts, and heating/cooling cycles, allowing theprocessing line to continue operating until the geometric sensors can bephysically recalibrated during a planned shutdown.

In various embodiments, virtual calibration systems and methods may beimplemented along processing lines of facilities that manufacture woodor wood-based products such as lumber, veneer, and engineered woodbeams, sheet materials, and the like. As an example, FIGS. 10-14 and thecorresponding text describe possible implementations of virtualcalibration systems along two processing lines of a lumber manufacturingfacility. This example is provided merely by way of explanation, and theimplementation and use of virtual calibration systems and methods inother types of facilities, with other types and arrangements ofequipment, will be readily apparent to those with ordinary skill in theart in possession of the present disclosure. Such alternatives areexpressly contemplated and encompassed herein.

Referring now to FIGS. 10-11, FIG. 10 illustrates a lumber processingsystem 1000 with a primary processing line 1000 a and a secondaryprocessing line 1000 b, and FIG. 11 shows a side elevational view ofprimary processing line 1000 a and corresponding operations of acomputer system.

Primary breakdown line 1000 a may include a log turner 1010, a chipper1012, saws 1016, and a transport system 1008 configured to convey logs10 and cants 12 (and optionally, center cants 14) along a path of flowthat extends through the log turner and the cutting devices. Many otherconfigurations are also possible. For example, a primary breakdown linemay have a saw center (e.g., one or more band saws or paired circularsaws) upstream of saws 1016 instead of a chipper. As another example, aprofiler module may be provided between chipper 1012 and saws 1016, orcombined with saws 1016 in a single module.

Transport system 1008 may include any suitable number, type(s), andcombination of transfers, conveyors, and/or positioning devices (e.g.,feed rolls, positioning pins/rolls, hold down rolls, lifts, skids/pans,ramps, etc.). Transport system 1008 may define a path of flow throughthe log turner 1010, chipper 1012, and saws 1016. For example, transportsystem 1008 may include a flighted chain conveyor that transports logsto the log turner, a sharp chain conveyor that transports the logsinto/through chipper 1012, and another conveyor and/or paired feed rollsthat feed the resulting cants into saws 1016. Optionally, transportsystem 1008 may be selectively operable to skew and/or slew the logs orcants while feeding them into or through the chipper, saws, or othermachine center.

Log turner 1010, chipper 1012, and saws 1016 may be conventional devicesof any suitable configuration. For example, log turner 1010 may be aroll-type, ring-type, sharp chain-type, rotary, knuckle, or other typeof log turner. Chipper 1012 may have one or more conical, drum-style, orother type of chip heads. Optionally, chipper 1012 may be achipper-canter (e.g., a vee chipper-canter, horizontal chipper-canter,or vertical chipper-canter). Saws 1016 may include one or more band sawsand/or circular saws. For example, saws 1016 may be a quad bandmill or aquad arbor saw. The primary breakdown line 1000 a may further includeother handling or positioning devices such as positioning/feed rolls,hold down rolls, lift pans/skids, and the like.

In various embodiments, the secondary breakdown line 1000 b may includean edger infeed 1022 a, an edger 1030, an edger outfeed 1022 b, and atransport system 1018 configured to convey cut pieces of wood (e.g.,flitches, cants, or slabs) from transport system 1008 to edger infeed1022 a. Any or all of these components may be conventional. Transportsystem 1018 may have any suitable number and combination of transfers,conveyors, positioning devices, and the like. For example, transportsystem 1018 may include a queuing deck, an unscrambler downstream of thequeuing deck, and a lugged chain conveyor between the unscrambler andthe edger infeed. Optionally, a lug loader and/or lumber indexingdevices such as duckers, pins/stops, or other such devices may beprovided between the unscrambler and the lugged chain conveyor to dealthe flitches into corresponding lug spaces. Other equipment may beprovided along transport system 1018, such as cross-cut saws, drop-outgates/diverters, ending rolls/positioning fences, overhead visioncameras, and the like. Although the transport system 1018 shown in FIG.10 includes a transverse conveyor, in other embodiments the transportsystem may be (or may include) a lineal conveyor.

Edger infeed 1022 a may be a conventional edger infeed with one or moreconveyors operable to move workpieces into the edger. Optionally, edgerinfeed 1022 a may include hold-down rolls above the conveyor(s). In someembodiments transport system 1018 and/or edger infeed 1022 a may includea positioning system selectively operable to place the flitches onto theedger infeed 1022 a in desired positions for cutting. For example, thepositioning system may include pins or conveyors that are independentlyoperable to position the flitches onto the ramps, and the ramps may beoperable to lower the repositioned flitches onto the edger infeed 1022a. In various embodiments, transport system 1018 and/or edger infeed1022 a may further include various other devices such as ending rolls,board/flitch turners, duckers/stops, drop-out gates, and the like.

Edger 1030 may be a straight-sawing, curve-sawing, gang, or other typeof edger. In some embodiments edger 1030 may be a conventional edgerwith one or more saws operable to cut flitches into boards. Optionally,edger 1030 may also include side chippers, a reman head, and/or otherfeatures.

The lumber processing system may have a scanner optimizer system thatincludes one or more scanners, each with at least one geometric sensor1002, and a computer system operatively coupled with thescanner(s)/geometric sensors. (Although some scanner optimizer systemsmay have scanning devices that do not include geometric sensors, theterm “scanner” as used herein refers exclusively to scanning deviceswith at least one geometric sensor.) Each scanner may be positioned toscan workpieces within a respective scan zone.

As shown for example in FIG. 10, a first scanner with geometric sensors1002 a may be positioned to scan logs 10 as they are conveyed ontransport system 1008 through a first scan zone located upstream of thelog turner 1010. A second scanner with geometric sensors 1002 b may bepositioned to scan the logs in a second scan zone located near the logturner 1010, just downstream of the log turner (FIG. 10) or justupstream of the log turner (FIG. 11). A third scanner with geometricsensors 1002 c may be positioned to scan the logs 10 or cants 12 in athird scan zone located between the second scan zone and the saws 1016,either upstream or downstream of the chipper 1012. A fourth scanner withgeometric sensors 1002 d may be positioned downstream of the saws 1016to scan the center cants 14 in a fourth scan zone after flitches 16 aresawn from the cants 12. A fifth scanner with geometric sensors 1002 emay be positioned to scan the flitches 16 in a fifth scan zone locatedalong transport 1018 upstream of edger 1030.

In various embodiments, each of the first, second, and third scanners ofthe primary processing line may include two or more geometric sensors.In a particular embodiment each of the first, second, and third scannersof the primary processing line includes at least one group of four orfive geometric sensors arranged around the path of flow (see e.g., FIGS.2A-C), the fourth scanner includes two geometric sensors arranged aboveand below, or on opposite sides of, the path of flow (see e.g., FIGS.2D, 2E), and the fifth scanner along the secondary processing lineincludes one or more rows of geometric sensors above and/or below theflow path, with 6-14 geometric sensors in each row (see FIGS. 3A-C). Anyor all of these scanners may include one or more additional groups ofgeometric sensors arranged to form sub-zones of the corresponding scanzone (see e.g., FIG. 11). For example, as illustrated in FIG. 11, thegeometric sensors 1002 a of the first scanner may be arranged to formtwo sub-zones, and the geometric sensors 1002 c of the third scanner maybe arranged to form two sub-zones. The number, locations, andarrangement of scanners and geometric sensors varies among embodiments,and such variations will be readily apparent to those with ordinaryskill in the art.

The scanner optimizer system may include any suitable number ofcomputers and computer systems. For example, in a facility with aprimary processing line and a secondary processing line, the scanneroptimizer system may include a first computer system 1006 operativelycoupled with some or all of the geometric sensors 1002 of the primaryprocessing line and a second computer system 1026 operatively coupledwith some or all of the geometric sensors 1002 of the secondaryprocessing line. Optionally, the scanner optimizer system may furtherinclude a third computer system 1014 operatively coupled with computersystem 1006 and/or 1026. Alternatively, the scanner optimizer system mayinclude only one or two, or more than three, computer systems. Any orall of the computer systems may include, or may be operatively coupledwith, one or more output devices 1028 such as monitors, speakers,projectors, portable electronic devices (e.g., laptops, tablets,netbooks, smartphones), and/or other devices used within the facility tomonitor operations therein.

Each computer system may include one or more computers, programmablelogic controllers, and/or motion controllers, in any suitable number andcombination. For example, first computer system 1006 may includecomputers 1006 a, 1006 b, 1006 c, and 1006 d operatively coupled withcorresponding geometric sensors (e.g., geometric sensors 1002 a, 1002 b,1002 c, and 1002 d, respectively), and may optionally include one ormore controllers 1020 a, 1020 b, 1020 c operatively coupled with one ormore of the computers. Second computer system 1026 may include acomputer operatively coupled with geometric sensors 1002 e, and mayoptionally include one or more controllers (e.g., 1020 d) operativelycoupled with the computer. In various embodiments, each of thecontrollers 1020 a, 1020 b, 1020 c, and 1020 d may include aprogrammable logic controller (PLC) and a motion controller incommunication with the PLC and a corresponding machine center (e.g., logturner 1010, chipper 1012, saws 1016, edger 1030) and/or handlingequipment (e.g., centering/feed rolls, hold down rolls, conveyor(s),positioning pins, and the like). Signals may be transmitted from thecomputer to the PLC, from the PLC to the motion controller, and from themotion controller to the machine center or handling equipment, and viceversa. However, in some embodiments a PLC may send signals directly to amachine center and/or handling equipment, and the motion controller maybe omitted or arranged to communicate directly with the computer.

In some embodiments, the scanner optimizer system or computer system(s)may further include one or more position indicator devices, such asphoto-eyes 1024 a and/or encoders 1024 b, configured to generate dataused by the scanner optimizer system to determine and/or control theposition and/or travel speed of workpieces on transport systems1008/1018. Other examples of position indicator devices include, but arenot limited to, overhead cameras, light curtains, linear positionsensors/transducers, and the like. The number, type, and placement ofposition indicator devices may vary among embodiments. For example, theposition indicator device(s) may be used by the scanner optimizer systemto coordinate operations of the sensors, conveyor systems, cuttingdevices, positioning/handling equipment, and/or data transfer amongcomputer systems performing the methods described herein. In someembodiments position indicator devices may also be used by the scanneroptimizer system to aid in matching profile data received from multiplescanners for a given workpiece (e.g., by synchronizing data capture ormatching frames along the Z-axis of the workpiece).

As workpieces are conveyed along the processing lines and through thesuccessive scan zones, the respective computer systems may use theprofile data collected by the scanners to determine how the workpiecesshould be positioned for the next stage of processing, how they shouldbe cut, and how the positioning and cutting devices should be moved andoperated to reposition and cut the workpiece. This may require thecomputer system(s) to compare and match profile data from two scannersor from two geometric sensors of the same scanner. Misalignment of oneof the scanners or geometric sensors relative to the other may impedethe matching process.

Therefore, a virtual calibration system may be implemented along eitheror both of the processing lines. Operations of the processing lines 1000a and 1000 b before and after implementation of a virtual calibrationsystem are described below by way of example.

Before Implementation of a Virtual Calibration System:

Without a virtual calibration system, processing lines 1000 a and 1000 bmay operate generally as follows. First transport system 1008 may conveya log 10 through the first scan zone to the log turner 1010. Computer1006 a may receive the profile data from the geometric sensors 1002 aand may generate a 3D model of the log by assembling the received datapoints, or by interpolating between the groups of data points of thereceived set of profile data to create new groups of data points atdesired intervals (e.g., for cross sections on ½ inch centers) along thelongitudinal axis of the log and assembling the new groups of datapoints. Computer system 1006 a may use the 3D model to determine adesired rotational position, and optionally a desired skew/slewposition, for the log. For example, computer system 1006 a may determinethe desired position based on the predicted stability of the log indifferent positions on a conveyance (e.g., a sharp chain) and/or thevalue of potential cut solutions for the log in some or all of thosepositions. Computer 1006 a may send the desired rotational position andthe received profile data, and optionally the 3D model and/or otherdata, to computer 1006 b. In addition, computer 1006 a may send thereceived profile data and/or 3D model to computer 1006 c. Computer 1006a may also send commands to a computer display/monitor to display the 3Dvirtual model, actual position, desired rotational position, and/orother information about the log.

The log may be scanned again by geometric sensors 1002 b while the logturner is turning the log and advancing the log in the flow direction.As computer 1006 b receives the cross sections (groups of data points)from geometric sensors 1002 b, computer 1006 b may compare them to thecorresponding cross sections of the profile data obtained by geometricsensors 1002 a and calculate the rotational differences. Computer 1006 bmay use the determined rotational differences to monitor changes in therotational angle of the log, relative to the initial orientation of thelog at the first scan zone. Based on the detected rotational differences(and optionally, additional factors such as the rotation speed of thelog turner, conveyor speed, log diameter, and the like), computer 1006 bmay identify and/or predict turn error and generate commands to adjustoperation of the log turner accordingly (e.g., to speed up, slow down,or reverse the direction of rotation, and/or to perform another rotationof the log) to turn the log toward the desired rotational position.After the log has been turned, and optionally skewed/slewed, the log maybe deposited onto the next portion of first transport system 1008 (e.g.,a sharp chain) and conveyed through the third scan zone toward chipper1012 and saws 1016. Optionally, computer 1006 b may send commands to acomputer display/monitor to display the 3D virtual model, currentrotational position, desired rotational position, predicted final turnangle, turn angle error, and/or other such information.

Geometric sensors 1002 c may scan the log 10 (or the cant 12, if thescan zone is between the chipper 1012 and saws 1016). Computer 1006 cmay use the profile data from geometric sensors 1002 c to generate a new3D model of the log generally as described above (e.g., by assemblingthe received profile data or interpolating between the received crosssections to generate and assemble new cross sections). Computer 1006 cmay use the received set of profile data and/or new 3D model todetermine an optimized cut solution for the log and to generate commandsto control the chipper 1012 and saws 1016 to chip the log into a cantand cut flitches from the cant according to the optimized cut solution.Computer 1006 c may compare the sets of profile data from geometricsensors 1002 c and 1002 a (or corresponding 3D models) to determine afinal position of the log on the conveyance (e.g., a sharp chain).Optionally, computer 1006 c may compare the final position of the log toa cut solution and/or desired rotational position determined by computer1006 a, and adjust the cut solution (or calculate a new cut solution) tooffset a difference between the desired position of the log on the sharpchain and the actual position of the log on the sharp chain.Alternatively, computer 1006 c may use the set of profile data receivedfrom geometric sensors 1002 c and/or the corresponding 3D model todetermine an optimized cut solution for the log, and may generatecommands (e.g., to controller 1020 c) to control the saws 1016 to cutflitches from the cant according to the optimized cut solution. If thescan zone of geometric sensors 1002 c is upstream of the chipper 1012,computer 1006 c may also generate commands to control the chipper 1012to chip the log into the cant according to the optimized cut solution.Computer 1006 c may send commands to a computer display/monitor todisplay the 3D virtual model, final position, cut solution, and/or othersuch information.

The remaining center cant 14 may be conveyed through the fourth scanzone and scanned by geometric sensors 1002 d. Computer 1006 d may usethe profile data from geometric sensors 1002 d to create a 3D virtualmodel of the actual center cant as described above, and/or may apply thecut solution to a 3D virtual model generated by another computer (e.g.,computer 1006 a) to create a 3D model of the expected center cant. Inany case, computer 1006 d may use the profile data from geometricsensors 1002 d to assess the performance of the chipper or saws, and/orto generate commands to control downstream cutting equipment (e.g., agang saw) to cut the center cant into boards. For example, computer 1006d may compare one or more actual dimensions of the center cant (e.g.,the width of the cut faces, overall width of the cant, distances of thecut faces from the centerline/chain, etc.) to the expected dimensions ofthe center cant defined by the cut solution to determine whether thesaws 1016 and/or chipper 1012 are cutting the cant accurately, whetherany of the saws 1016 are ‘snaking,’ whether the chip heads are chippingat the correct distance from the center line/sharp chain, and the like.Computer 1006 d may send commands to a computer display/monitor, todisplay information about the performance of the saws 1016 and/orchipper 1012. Computer 1006 d may also send commands (e.g., to acontroller) to control another set of saws, such as a gang saw, to cutthe center cant into boards.

The flitches 16 may be diverted to the transport system 1018 andsingulated along the transport system 1018 (e.g., by an unscrambler)before passing individually through the scan zone of another scannerwith sensors 1002 e. The second computer system 1026 may use the set ofprofile data from geometric sensors 1002 e to generate a 3D model of theflitch as described above (e.g., by assembling the received profile dataor interpolating between the received cross sections to generate andassemble new cross sections). The second computer system 1026 may usethe 3D model to determine an optimized cut solution for the flitch, andmay use both the 3D model and the optimized cut solution to determine adesired position for the flitch relative to edger infeed 1022 a (i.e., aposition in which the flitch could be cut by the edger according to thecut solution). The second computer system 1026 may generate commands(e.g., to a controller) to control cutting and positioning equipment(e.g., edger infeed 1022 a, edger 1030, and/or positioning equipmentsuch as pins, belts, rollers, and the like) to reposition and cut theflitch into one or more boards according to the optimized cut solutionfor the flitch. The second computer system 1026 may send commands to acomputer display/monitor to display a 3D model of the flitch, the cutsolution for the flitch, the current or expected positions of the edgersaws relative to the current or expected position of the flitch, and/orother such information.

The third computer system 1014 may receive data from the first and/orsecond computer system(s) and use the data to perform any of theoperations attributed above to the other computers or computer systems.

As workpieces are processed, the geometric sensors may be subjected tovibration, impacts, heating/cooling cycles, and other such factors. Asthe geometric sensors become misaligned, the profile data obtained bythe geometric sensors also becomes misaligned relative to the profiledata from other geometric sensors. This may reduce the speed and/oraccuracy of the matching process performed by the computer system, whichmay in turn result in slower processing line speeds and/or less accuratecutting and positioning of workpieces.

After Implementation of a Virtual Calibration System:

Therefore, processing lines 1000 a and 1000 b may be provided with avirtual calibration system by programming any or all of computer systems1006, 1026, and/or 1014 to perform a virtual calibration method. Forexample, computer systems 1006 and 1026 may be programmed to performmethods 1200 and 1300, respectively, described in further detail below.Alternatively, computer systems 1006, 1026, and/or 1014 may beprogrammed to perform method 600. Regardless, the resulting virtualcalibration system may include the computer system(s) with suchprogramming and the geometric sensors that are operatively coupledthereto.

With a virtual calibration system, the processing lines 1000 a and 1000b may operate generally as follows. A log 10 may be conveyed on firsttransport system 1008 through the first scan zone to the log turner.Geometric sensors 1002 a may scan the log 10, and computer 1006 a mayreceive the profile data from the geometric sensors 1002 a. Optionally,computer system 1006 a may generate a 3D model of the log by assemblingthe received data points, or by interpolating between the groups of datapoints of the received set of profile data to create new groups of datapoints at desired intervals (e.g., for cross sections on ½ inch centers)along the longitudinal axis of the log and assembling the new groups ofdata points. Computer system 1006 a may use the 3D model to determine adesired rotational position, and optionally a desired skew/slewposition, for the log. For example, computer system 1006 a may determinethe desired position based on the predicted stability of the log indifferent positions on a sharp chain and/or the value of potential cutsolutions for the log in some or all of those positions. Computer 1006 amay send the desired rotational position and the received profile data,and optionally the 3D model and/or other data, to computer 1002 b. Inaddition, computer 1006 a may send the received profile data and/or 3Dmodel to computer 1006 c. Computer 1006 a may also send commands to anoutput device (e.g., output device 1028), such as a computerdisplay/monitor, to display the 3D virtual model, position information,and/or other information about the log via a user interface 1028 a. Insome embodiments, the profile data received from the geometric sensors1002 a may be used as the ‘reference’ profile data by computers 1002 b,1002 c, and/or 1002 d.

Alternatively, computer 1006 a may perform a virtual calibration methodto adjust the profile data received from geometric sensors 1002 a, anduse the adjusted set of profile data (instead of the profile datareceived from the geometric sensors 1002 a) to generate the 3D model.Computer 1006 a may then use the 3D model to perform the otheroperations described above with reference to computer 1006 a. Forexample, the virtual calibration system may further include anadditional scanner or geometric sensor(s) located upstream of geometricsensors 1002 a, and computer 1006 a may use the profile data receivedfrom that scanner or geometric sensor(s) as the ‘reference’ profiledata. In that case, computer 1006 a may determine the positional offsetsof profile data from geometric sensors 1002 a relative to thecorresponding ‘reference’ profile data, determine correction valuesbased on the offset values, and apply the correction values to theprofile data received from geometric sensors 1002 a to obtain theadjusted profile data. In such embodiments, the ‘reference’ profile dataobtained by the additional scanner/geometric sensors may also be used asthe ‘reference’ profile data by computers 1002 b, 1002 c, and/or 1002 d.Alternatively, the profile data obtained by geometric sensors 1002 a maybe used as the ‘reference’ profile data by any or all of thosecomputers. Optionally, computer 1006 a may also send commands to theoutput device to display the current correction values, offset values,misalignment warnings, and/or other information about the alignment ofgeometric sensors 1002 a instead of, or in addition to, the informationabout the log via the user interface 1028 a.

The log may be scanned again by geometric sensors 1002 b while the logturner is turning the log and advancing the log in the flow direction.However, instead of comparing the cross sections of profile datareceived from geometric sensors 1002 b to the corresponding crosssections received from geometric sensors 1002 a, computer 1006 b mayperform a virtual calibration method to adjust the profile data receivedfrom geometric sensors 1002 b, and may match the adjusted profile data(instead of the unadjusted profile data) to the profile data fromgeometric sensors 1002 a to determine the rotational differences.Computer 1006 b may use the determined rotational differences to monitorchanges in the rotational angle of the log, relative to the initialorientation of the log at the first scan zone. Based on the detectedrotational differences (and optionally, additional factors such as therotation speed of the log turner, conveyor speed, log diameter, and thelike), computer 1006 b may identify and/or predict turn error andgenerate commands to adjust operation of the log turner accordingly(e.g., to speed up, slow down, or reverse the direction of rotation,and/or to perform another rotation of the log) to turn the log towardthe desired rotational position, and optionally to skew/slew the log.After the log has been turned, and skewed/slewed if necessary, the logmay be deposited onto the next portion of first transport system 1008(e.g., a sharp chain) and conveyed through the third scan zone towardchipper 1012 and saws 1016.

After the log has been repositioned and deposited onto the next portionof first transport system 1008 (e.g., a sharp chain), and conveyedthrough the third scan zone, computer 1006 c may receive thecorresponding set of profile data from geometric sensors 1002 c. In someembodiments, computer 1006 c may use the profile data from geometricsensors 1002 c in the same manner as before the implementation of thevirtual calibration system. In other embodiments, computer 1006 c mayperform a virtual calibration method to adjust the profile data receivedfrom geometric sensors 1002 c, and may use the adjusted profile data inplace of the unadjusted profile data for various processing tasks. Forexample, computer 1006 c may match the adjusted profile data to theprofile data from the ‘reference’ scanner/geometric sensor (or match thecorresponding 3D models) to determine a difference between the expectedposition of the log on the sharp chain and the actual position of thelog on the sharp chain. In that case, computer 1006 c may adjust a cutsolution determined by computer 1006 a, and/or adjust the positions oroperation of downstream cutting or handling equipment, to offset thedifference. In some embodiments computer 1006 c may use the adjustedprofile data to generate a 3D model (e.g., by assembling the receivedprofile data or interpolating between the received cross sections togenerate and assemble new cross sections), and use the new 3D model todetermine an optimized cut solution for the log and to generate commandsto control the chipper 1012 and saws 1016 to chip and cut the logaccording to the optimized cut solution.

The remaining center cant may be conveyed through the fourth scan zone,and computer 1006 d may receive the profile data from geometric sensors1002 d. Optionally, computer 1006 d may perform a virtual calibrationmethod to adjust the received profile data, and may use the adjustedprofile data instead of the received profile data to assess theperformance of the chipper or saws, and/or to generate commands tocontrol downstream cutting equipment (e.g., a gang saw) to cut thecenter cant into boards. For example, computer 1006 d may match the newset of adjusted profile data to the adjusted profile data generated bycomputer 1006 c (or match the corresponding 3D models) to measureparameters such as the thicknesses of the flitches cut from the cantsand/or the locations of the cuts, and compare the measured parameters tothe expected parameters (e.g., as defined by the cut solution), toassess the accuracy of the cuts made by the saws 1016. In response todetermining that an actual parameter is different from an expectedparameter by more than a threshold amount or percentage (e.g., 0.001inch, or 0.05%), computer system 1006 d may send one or more commands toa controller (e.g., controller 1020 c) to adjust the position of thecorresponding saw 1016 and/or a downstream gang saw to offset the error.

The flitches may be diverted to the transport system 1018 and singulatedalong the transport system 1018 (e.g., by an unscrambler) before passingindividually through the scan zone of another scanner with sensors 1002e. The second computer system 1026 may receive the corresponding profiledata from sensors 1002 e. In some embodiments the computer system 1026may perform a virtual calibration method to adjust the received profiledata, and may use the adjusted profile data instead of the receivedprofile data in various processing tasks. For example, computer system1026 may use the adjusted profile data to generate a 3D model of theflitch (e.g., by assembling the adjusted profile data or interpolatingbetween the cross sections of the adjusted profile data to generate andassemble new cross sections). The second computer system 1026 may usethe 3D model to determine an optimized cut solution and a desiredposition for the flitch, and to generate commands to control cutting andpositioning equipment (e.g., edger infeed 1022 a, edger 1030) toreposition and cut the flitch into one or more boards according to theoptimized cut solution for the flitch.

In some embodiments, the third computer system 1014 may receive datafrom the geometric sensors and/or computer systems and use the data toperform some of the above operations, and/or other functions such asmonitoring or analyzing the performance of the processing lines,reoptimizing cut solutions offline, and the like. For example, in someembodiments the third computer system 1014 may receive the profile datafrom the geometric sensors (directly, or via computer system 1006 and/or1026), perform the virtual calibration method(s) to generate theadjusted profile data, and send the adjusted profile data to thecorresponding computer system(s) for use.

In any case, the computer system(s) performing the virtual calibrationmethod(s) may determine and apply correction values continuously orsemi-continuously to incoming profile data as the processing lineoperates. Thus, in addition to generating adjusted profile data that canbe matched more readily to profile data from other geometricsensors/scanners, the computer system(s) may track changes in therelative positions of the geometric sensors. If the correction value fora given sensor exceeds a threshold value, the computer system(s) maygenerate an alert to indicate to the operator that the physical positionof the geometric sensor requires adjustment. Programming the computersystem(s) to virtually calibrate the geometric sensors may improve theperformance of the computer system(s) by simplifying the matchingprocess to reduce the computational load on the processor and/orincrease the rate at which the computer system can match the profiledata. Regardless, the adjusted data may allow the system to run longerand perform better without stopping for manual calibration/alignment

FIGS. 12 and 13 illustrate embodiments of a single-zone virtualcalibration method 1200 and a multi-zone virtual calibration method1300, respectively. For clarity, method 600 encompasses single-zone andmulti-zone applications, and methods 1200 and 1300 may be consideredembodiments of method 600. Therefore, the description of method 600 (andmethods 700, 800, and 900) also applies to methods 1200 and 1300 unlessotherwise indicated.

Referring now to FIG. 12, at block 1201 the computer system (e.g.,computer system 1006 and/or 1014, computer 1006 a/b/c/d) may receiveprofile data from a first scanner with multiple geometric sensors (e.g.,geometric sensors 1002 a/b/c/d). At block 1203, the computer system mayapply current correction values (if any) to the profile data from thefirst scanner to obtain adjusted profile data. As described below withregard to block 1211, each of the current calibration values may be theaverage of a desired number of the most recent offset values stored in acorresponding buffer, or some other appropriate filter of the data.

At block 1205 the computer system may send the adjusted profile data toa machine center and/or use the adjusted profile data for variousprocessing tasks. In some embodiments, the computer system may match theadjusted profile data to profile data from another scan zone todetermine a change in workpiece position, size, shape, or the like. Forexample, computer 1006 b may adjust the profile data received fromgeometric sensors 1002 b, compare the cross sections of the adjustedprofile data to the corresponding cross sections of the profile dataobtained by geometric sensors 1002 a to determine the rotationaldifferences between the matched cross sections, and use the determinedrotational differences to monitor changes in the rotational angle of thelog while the log is rotated by the log turner. Based at least on thedetected rotational differences, (and optionally, additional factorssuch as the rotation speed of the log turner, conveyor speed, logdiameter, feedback from position indicators such as encoders and/orphoto-eyes, and the like), computer 1006 b may identify and/or predictturn error or final rotation angle and generate commands to adjustoperation of the log turner accordingly (e.g., to speed up, slow down,or reverse the direction of rotation, and/or to perform another rotationof the log) to turn the log toward the desired rotational position. Forexample, computer 1006 b may use such the detected differences topredict the log's final rotational angle, compare the predicted finalrotational angle to the desired/optimized rotational angle, anddetermine a difference between the two angles. Based on the difference,computer 1006 b may generate commands to a controller (e.g., 1020 a ofFIG. 10), such as a programmable logic controller (PLC) and a motioncontroller, to speed up, slow down, or reverse the direction of rotationby the log turner 1010 during the turn, or to turn the log again after afirst rotation, until the log is substantially in the desired position.In some embodiments, the computer system may use adjusted profile datato generate a 3D virtual model of the workpiece and determine a cutsolution and/or desired position for the workpiece based on the 3Dvirtual model.

At block 1207 the computer system may compare the profile data receivedfrom the first geometric sensors (e.g., geometric sensors 1002 b) to acorresponding reference set of profile data from the geometric sensorsof a second scanner (e.g., geometric sensors 1002 a) located upstream ordownstream of the first geometric sensors to identify a matching frameof the reference set of profile data. The computer system may identifythe matching frame of the reference set of profile data in any suitablemanner, such as by pairwise comparison of frames or data points andselection of the match with the highest comparison score.

At block 1209 the computer system may align the set of profile data fromthe first scanner to the reference set of profile data from the secondscanner. At block 1211 the computer system may align the profile datafrom each of the first geometric sensors to the reference set of profiledata to obtain corresponding translation and/or rotation values for thefirst geometric sensors. The computer system may store these values asoffset values in corresponding buffers at block 1213. In someembodiments, an offset value may be an X-Y offset. In other embodiments,an offset value may include an X-Y offset and a rotational offset (e.g.expressed in degrees).

At block 1215 the computer system may calculate the average of a desirednumber (e.g., 50) of the most recent offset values in each buffer toobtain a current correction value for each of the first geometricsensors. Optionally, at block 1217 the computer system may display thecalibration value(s) and/or cause an output device to display or emit analarm to indicate that a calibration value has exceeded a threshold. Insome embodiments, block 1217 may proceed as illustrated in FIG. 9 andthe corresponding description. From block 1215 or block 1217, the methodmay return to block 1201 as the computer system receives a new set ofprofile data from the first geometric sensors for another workpiece(e.g., a log), and the process may be repeated.

While the method of FIG. 12 is described in the context of primaryprocessing line 1000 a, the method may also be performed to virtuallycalibrate one scanner relative to another scanner along processing linesof other types and configurations.

Turning now to FIG. 13, at block 1301 a computer system (e.g., computersystem 1026 or 1014) may receive a set of profile data from a firstscanner that includes a plurality of geometric sensors with overlappingfields of view (e.g., geometric sensors 102 e). At block 1303 thecomputer system may apply current correction values to the set ofprofile data to obtain an adjusted set of profile data. At block 1305the computer system may send the adjusted set of profile data to anothercomputer system, computer, or machine center, and/or use the adjustedset of profile data in various processing tasks. For example, thecomputer system 1026 may use the adjusted set of profile data instead ofthe set of profile data from geometric sensors 1002 e to generate the 3Dmodel of the flitch (e.g., by assembling the received profile data orinterpolating between the received cross sections to generate andassemble new cross sections). Computer system 1026 may use the 3D modelto determine an optimized cut solution and a desired position for theflitch. Computer system 1026 may generate commands to control cuttingand positioning equipment (e.g., edger infeed 1022 a, edger 1030) toreposition the flitch to the desired position and cut the flitch intoone or more boards according to the optimized cut solution.

If there are no current correction values for the geometric sensors,blocks 1303 and 1305 may be omitted and the method may proceed to block1307.

At block 1307 the computer system may align the profile data from eachof the geometric sensors to the overlapping portion(s) of data from theother geometric sensor(s) of the scanner to obtain corresponding offsetvalues. Again, in some embodiments the offset values may be X-Y offsets.In other embodiments, the offset values may include X-Y offsets androtational offsets. At block 1309 the computer system may store theoffset values in corresponding buffers.

At block 1311 the computer system may determine an offset value for eachof the geometric sensors based on one or more of the offset valuesstored in the corresponding buffer. For example, the offset value may bethe average of a desired number (e.g., 50) offset values in thecorresponding buffer. Optionally, at block 1311 the computer system maydisplay the correction values and/or cause an output device to displayor emit an alarm to indicate that a correction value has exceeded athreshold. In some embodiments, block 1311 may proceed as illustrated inFIG. 9 and the corresponding description. From block 1309 or block11311, the method may return to block 1301 as the computer systemreceives a new set of profile data from the geometric sensor for anotherworkpiece (e.g., a flitch), and the process may be repeated.

While the method of FIG. 13 is described in the context of secondaryprocessing line 1000 b, the method may also be performed to virtuallycalibrate one geometric sensor of a scanner relative to anothergeometric sensor of the same scanner along processing lines of othertypes and configurations.

FIG. 14 illustrates an example of a process flow 1400 for performing avirtual calibration method, in accordance with various embodiments. Uponinitiation at block 1401, the process may proceed to block 1403. Atblock 1403, the computer system may determine whether a new set ofprofile data has been received. The new set of profile data may beprofile data obtained by a first geometric sensor or scanner. If thecomputer system determines that a new set of profile data has not beenreceived, the computer system may check periodically for a new set ofprofile data. If the computer system determines that a new set ofprofile data has been received, the computer system may optionallygenerate a 3D model based on the received set of profile data.Alternatively, block 1405 may be omitted and the process may proceedfrom block 1403 to block 1407. At block 1407 the computer system maydetermine whether a reference set of profile data has been received. Thereference set of profile data may be profile data obtained by a secondgeometric sensor or scanner for the same object (e.g., a piece of wood).Again, the computer system may check periodically for reference profiledata until the computer system determines that reference data has beenreceived. In some embodiments the computer system may determine at block1407 that the received set of profile data matches a correspondingreference set of profile data. Alternatively, the computer system maydetermine matches later in the process (e.g., at block 1413, or betweenblocks 1407 and 1413).

At block 1409 the computer system may check one or more buffers foroffset values. A buffer may store offset values for a particular firstgeometric sensor (e.g., geometric sensor 102 b), and each offset valuein the buffer may represent the X-Y offset (and optionally, a rotationaldifference) of prior profile data from the first geometric sensor(s)relative to reference profile data from another geometric sensor (e.g.,geometric sensor 102 a). If the first scanner includes multiple firstgeometric sensors, the computer system may check the correspondingbuffers for offset values. At block 1411 the computer system maydetermine whether the buffer(s) have at least a desired number of offsetvalues (e.g., 1, 10, 20, 50 offset values per buffer).

If the computer system determines that there are no offset values in thebuffer(s), or that there are fewer than the desired number of offsetvalues in the buffer(s), the process may proceed to block 1413.Alternatively, if the computer system determines at block 1407 that theprofile data matches the set of reference profile data, the process mayproceed from block 1407 to block 1413. In other embodiments the processmay proceed to block 1413 from any of blocks 1403, 1405, 1407, 1409,1411, 1421, or 1423.

At block 1413 the computer system may identify a frame of the referenceset of profile data that matches a frame of the new set of profile data.At block 1415 the computer system may align the new set of profile datato the reference set of profile data, or align the two frames.Optionally, if the new set of profile data and the reference set ofprofile data include data from multiple geometric sensors, at block 1417the computer system may align each portion of the new set of profiledata to the reference profile data to obtain offset values for thecorresponding first geometric sensors. Alternatively, block 1417 may beomitted, and the computer system may obtain the offset value(s) at block1415 by aligning the two sets or frames of profile data. Regardless, atblock 1419 the computer system may store the offset value(s) in thebuffer(s), and the process may then return to block 1403.

If the computer system determines at block 1411 that the buffer(s)contain at least the desired number of offset values, the process mayproceed to block 1421. At block 1421 the computer system may determineone or more correction values based on the offset value(s) in thebuffer(s). In some embodiments a correction value may be the most recentoffset value in the corresponding buffer. In other embodiments acorrection value may be the average of the desired number of most recentoffset values stored in the corresponding buffer. Alternatively, acorrection value may be determined based on the offset values in anyother suitable manner. At block 1423 the computer system may apply thecorrection value(s) to the new set of profile data to obtain an adjustedset of profile data.

Optionally, the computer system may send the adjusted set of profiledata to a machine center and/or another computer system (block 1425),display the correction value(s) (block 1427), and/or generate an alertto indicate that a correction value exceeds a threshold value (block1429). Regardless, the process may proceed from any of blocks 1423-1429to block 1413, and the process may continue at block 1413 and thereafteras described above.

In other embodiments, a virtual calibration system may be implementedalong processing lines of any type and configuration in facilities suchas sawmills, planer mills, plywood mills, or the like. Again, if thefacility has existing geometric sensors (e.g., geometric scanners 102)with overlapping fields of view and an existing computer system, avirtual calibration system may be implemented by programming theexisting computer system to perform one or more of the virtualcalibration methods disclosed herein. Alternatively, a virtualcalibration system may be implemented by installing any components ofthe virtual calibration system that the facility lacks (e.g., one ormore of the geometric sensors and/or the programmed computer system).

FIG. 15 illustrates an example of a computer system 1550 suitable forperforming a virtual calibration method, and optionally other processesdescribed herein, all in accordance with various embodiments. Computersystem 1550 may have some or all of the functionality and features ofany or all of the computers and computer systems described herein (e.g.,computer system(s) 106, 1006, 1026, 1014, computer(s) 1006 a, 1006 b,1006 c, 1006 d).

As illustrated, computer system 1550 may include system control logic1556 coupled to at least one of the processor(s) 1554, memory 1552coupled to system control logic 1556, non-volatile memory (NVM)/storage1558 coupled to system control logic 1556, and one or morecommunications interface(s) 1560 coupled to system control logic 1556.In various embodiments, system control logic 1556 may be operativelycoupled with geometric sensors (e.g., geometric sensors 102, 102 a/b,1002 a/b/c/d/e) with sensor logic 1586. Optionally, system control logic1556 may also be operatively coupled with one or more other sensors(e.g., sensors 132), output devices (e.g., output device 128), and/orcontrollers (e.g., controller 120 a/120 b/120 c). In various embodimentsthe processor(s) 1554 may be a processor core.

System control logic 1556 may include any suitable interfacecontroller(s) to provide for any suitable interface to at least one ofthe processor(s) 1554 and/or any suitable device or component incommunication with system control logic 1556. System control logic 1556may also interoperate with the sensors and/or the output device(s). Invarious embodiments, the output device may include a display.

System control logic 1556 may include one or more memory controller(s)to provide an interface to memory 1552. Memory 1552 may be used to loadand store data and/or instructions, for example, for various operationsof lumber processing system 1000 a/1000 b. In one embodiment, systemmemory 1552 may include any suitable volatile memory, such as suitabledynamic random-access memory (“DRAM”).

System control logic 1556, in one embodiment, may include one or moreinput/output (“I/O”) controller(s) to provide an interface toNVM/storage 1558 and communications interface(s) 1560.

NVM/storage 1558 may be used to store data and/or instructions, forexample. NVM/storage 1558 may include any suitable non-volatile memory,such as flash memory, for example, and/or any suitable non-volatilestorage device(s), such as one or more hard disk drive(s) (“HDD(s)”),one or more solid-state drive(s), one or more compact disc (“CD”)drive(s), and/or one or more digital versatile disc (“DVD”) drive(s),for example.

The NVM/storage 1558 may include a storage resource that may physicallybe a part of a device on which computer system 1550 is installed, or itmay be accessible by, but not necessarily a part of, the device. Forexample, the NVM/storage 1558 may be accessed over a network via thecommunications interface(s) 1560.

System memory 1552, NVM/storage 1558, and/or system control logic 1556may include, in particular, temporal and persistent copies ofcalibration logic 1574. The calibration logic 1574 may includeinstructions operable, upon execution by at least one of theprocessor(s) 1554, to cause computer system 1550 to perform one or moreof the virtual calibration methods described herein (e.g., method 600,700, 800, 900, 1200, 1300, 1400), or various operations thereof.Optionally, system memory 1552, NVM/storage 1558, and/or system controllogic 1556 may further include temporal and persistent copies ofoptimization logic 1576. The optimization logic 1576 may includeinstructions operable, upon execution by at least one of theprocessor(s) 1554, to cause computer system 1550 to perform variousother operations, such as generating 3D models based onreceived/adjusted profile data, matching sets of profile data or 3Dmodels, determining a desired position for a workpiece upstream of acutting device, determining a cut solution for the workpiece, generatingcommands to a controller, machine center, or workpiece handling deviceto position or cut the workpiece, and the like.

Communications interface(s) 1560 may provide an interface for computersystem 1550 to communicate over one or more network(s) and/or with anyother suitable device. Communications interface(s) 1560 may include anysuitable hardware and/or firmware, such as a network adapter, one ormore antennas, a wireless interface, and so forth. In variousembodiments, communication interface(s) 1560 may include an interfacefor computer system 1550 to use NFC, optical communications (e.g.,barcodes), BlueTooth or other similar technologies to communicatedirectly (e.g., without an intermediary) with another device. In variousembodiments, the wireless interface may interoperate with radiocommunications technologies such as, for example, WCDMA, GSM, LTE, andthe like.

The capabilities and/or performance characteristics of processors 1554,memory 1552, and so forth may vary. In various embodiments, computersystem 1550 may include, but is not limited to, a smart phone, acomputing tablet, a laptop computer, a desktop computer, and/or aserver. In various embodiments computer system 1550 may be, but is notlimited to, one or more servers known in the art.

In one embodiment, at least one of the processor(s) 1554 may be packagedtogether with system control logic 1556, calibration logic 1574, and/oroptimization logic 1576. For example, at least one of the processor(s)1554 may be packaged together with system control logic 1556,calibration logic 1574, and/or optimization logic 1576 to form a Systemin Package (“SiP”). In another embodiment, at least one of theprocessor(s) 1554 may be integrated on the same die with system controllogic 1556, calibration logic 1574, and/or optimization logic 1576. Forexample, at least one of the processor(s) 1554 may be integrated on thesame die with system control logic 1556, calibration logic 1574, and/oroptimization logic 1576 to form a System on Chip (“SoC”).

The computer system 1550 may be configured to perform any or all of thecalculations, operations, and/or functions described herein, includingthe methods and operations described with reference to FIGS. 6-9, 12-14,and any of the other Figures.

Therefore, in some embodiments, a virtual calibration system may beimplemented along an existing workpiece processing line. If theworkpiece processing line has two or more geometric sensors withoverlapping fields of view and a computer system operatively coupledwith the geometric sensors, the virtual calibration system may beimplemented by programming the existing computer system to perform oneor more of the virtual calibration methods disclosed herein, or byoperatively coupling another computer system programmed to perform suchmethod(s) with the existing geometric sensors. Similarly, if theworkpiece processing line lacks at least two geometric sensors withoverlapping fields of view, a virtual calibration system may beimplemented by providing the geometric sensors in a suitable arrangementand operatively coupling the geometric sensors with a computer systemprogrammed to perform the method(s).

Another aspect of the present disclosure is a virtual calibration systemthat comprises a first and a second geometric sensor and a computersystem operatively coupled with the first and second geometric sensors,the computer system programmed with instructions operable, uponexecution by a processor of the computer system, to perform one or moreof the virtual calibration methods described and/or claimed herein.

Another aspect of the present disclosure is a computer-readable storagemedium programmed with instructions operable, upon execution by aprocessor, to perform one or more of the virtual calibration methodsdescribed and/or claimed herein.

Another aspect of the present disclosure is a computer program productcomprising non-transitory computer-readable instructions operable, uponexecution by a processor, to cause the processor to perform one or moreof the virtual calibration methods described and/or claimed herein.

Another aspect of the present disclosure is a method of upgrading aworkpiece processing line, wherein the workpiece processing lineincludes at least two geometric sensors with overlapping fields of viewarranged to scan workpieces moving along a flow path, the methodcomprising operatively coupling the geometric sensors with a computersystem programmed to perform one or more of the virtual calibrationmethods described and/or claimed herein.

Although certain embodiments have been illustrated and described herein,it will be appreciated by those of ordinary skill in the art that a widevariety of alternate and/or equivalent embodiments or implementationscalculated to achieve the same purposes may be substituted for theembodiments shown and described without departing from the scope. Thosewith skill in the art will readily appreciate that embodiments may beimplemented in a very wide variety of ways. This application is intendedto cover any adaptations or variations of the embodiments discussedherein. Therefore, it is manifestly intended that embodiments be limitedonly by the claims and the equivalents thereof.

What is claimed is:
 1. A virtual calibration method comprising:receiving a first set of profile data obtained by one or more firstgeometric sensors, and a reference set of profile data obtained by oneor more second geometric sensors, for a first portion of a firstworkpiece, wherein the sets of profile data include overlapping profiledata; determining, based at least on the first set of profile data andthe reference set of profile data, a first one or more offset valuesthat represents a translational difference of the first set of profiledata, or portions thereof, relative to the reference set of profiledata; receiving a second set of profile data obtained by the one or morefirst geometric sensors, wherein the second set of profile datarepresents a second portion of the first workpiece or a portion of asecond workpiece; and generating an adjusted set of profile data for thesecond workpiece based at least on the second set of profile data andthe first one or more offset values to thereby offset a positional errorof the one or more first geometric sensors relative to the one or moresecond geometric sensors.
 2. The method of claim 1, wherein the one ormore first geometric sensors is a single first geometric sensor, and thefirst one or more offset values is a first offset value, and whereindetermining the first one or more offset values includes aligning thefirst set of profile data to the reference set of profile data based atleast in part on the overlapping profile data, determining an offset ofthe first set of profile data relative the reference set of profile databased on the alignment, wherein the offset includes an X-Y offset and/ora rotational offset, and storing the determined offset in a first bufferas the first offset value.
 3. The method of claim 2, wherein generatingthe adjusted set of profile data includes determining a correction valuebased at least on the first offset value, and applying the one or morecorrection values to the second set of profile data to thereby generatethe adjusted set of profile data.
 4. The method of claim 3, whereindetermining the correction value includes determining an average of aplurality of offset values stored in the first buffer, and the pluralityof offset values includes the first offset value.
 5. The method of claim4, wherein the plurality of offset values is a predetermined number ofthe most recent offset values stored in the first buffer, and thecorrection value is the determined average of said plurality of offsetvalues.
 6. The method of claim 3, wherein the single first geometricsensor is positioned to scan the workpieces in a first scan zone, andthe one or more second geometric sensors is positioned to scan theworkpieces in a second scan zone that is spaced apart from the firstscan zone along a flow path.
 7. The method of claim 3, wherein thesingle first geometric sensor and the one or more second geometricsensors are positioned to scan the workpieces in a first scan zone. 8.The method of claim 1, wherein the one or more first geometric sensorsis a plurality of first geometric sensors positioned to scan theworkpieces in a first scan zone, each of said portions of the first setof profile data is a portion of profile data obtained by a correspondingone of the first geometric sensors, and the first one or more offsetvalues is a plurality of first offset values, wherein determining theone or more first offset values includes aligning the first set ofprofile data to the reference set of profile data, aligning the portionsof profile data to the reference set of profile data, determining anoffset of each said portion of profile data relative to the referenceset of profile data based on the alignment, wherein each of the offsetsincludes an X-Y offset and/or a rotational offset, and storing thedetermined X-Y offsets in a corresponding plurality of buffers as theoffset values, such that each of the buffers includes the first offsetvalue for a corresponding one of the first geometric sensors.
 9. Themethod of claim 8, wherein generating the adjusted set of profile dataincludes determining a plurality of correction values based at least onthe first offset values, and applying the correction values to thesecond set of profile data to thereby generate the adjusted set ofprofile data.
 10. The method of claim 9, wherein determining thecorrection values includes determining an average of at least some ofthe offset values stored in each of the buffers, and wherein thedetermined averages are the correction values for the respective firstgeometric sensors
 11. The method of claim 10, wherein determining thecorrection values includes determining an average of a desired number ofthe most recent offset values stored in each of the buffers.
 12. Themethod of claim 9, wherein the one or more second geometric sensors ispositioned to scan the workpieces in a second scan zone that is spacedapart from the first scan zone along a flow path.
 13. The method ofclaim 9, wherein the one or more second geometric sensors is positionedto scan the workpieces in the first scan zone.
 14. The method of claim3, further including generating an alert based at least in part on thefirst offset value.
 15. The method of claim 14, wherein generating thealert includes comparing the correction value to a threshold value,determining, based on the comparison, whether the correction valueexceeds the threshold value, and in response to determining that thecorrection value exceeds the threshold value, sending a command to anoutput device to generate an alert message to thereby alert an operatorof a misalignment of the first geometric sensor relative to the secondgeometric sensor.
 16. The method of claim 9, further includinggenerating an alert based at least in part on one of the first offsetvalues.
 17. The method of claim 16, wherein generating the alertincludes comparing the correction values to a threshold value,determining, based on the comparison, whether the correction valueexceeds the threshold value, and in response to determining that thecorrection value exceeds the threshold value, sending a command to anoutput device to generate an alert message to thereby alert an operatorof a misalignment of a corresponding one of the first geometric sensorsrelative to the one or more second geometric sensors.
 18. The method ofclaim 1, wherein the workpieces are pieces of wood, the method furtherincluding controlling one or more machine centers to cut and/orreposition the second workpiece based at least in part on the adjustedset of profile data.
 19. The method of claim 1, wherein the workpiecesare logs, the one or more first geometric sensors is a plurality ofgeometric sensors positioned to scan the logs in a first scan zonelocated near a log turner, and the one or more second geometric sensorsis a plurality of geometric sensors positioned to scan the logs in asecond scan zone located upstream of the first scan zone, the methodfurther including: comparing the adjusted set of scan data to thereference set of scan data to determine a current position of the secondworkpiece; and controlling the log turner to reposition the secondworkpiece based at least on a difference between the current positionand a desired position.
 20. The method of claim 1, wherein theworkpieces are flitches, and the first and second geometric sensors arepositioned to scan the flitches upstream of an edger, the method furtherincluding: determining a cut solution for the flitch based at least onthe adjusted set of profile data; and controlling the edger to cut thesecond workpiece according to the cut solution.